Improvement in valve-gear for steam-engines



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AM. PHOTD LITHO. C0. NAY. (USBORNES PRUCESS) UNiTED STATES PATENT OFFICE.

EDWARD N. DIoxERsoN, 0E NEW YORK, N. Y.

IMPROVEMENT IN VALVE-GEAR. FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 39,278, dated July 21, 1863.

.To all whom it may concern.-

Be it known that 1, EDWARD N. DrcKER- SON, of N ew York city, have invented a new and useful improvement in the means of Working the. valves of steam-engines by hand 5 and I do hereby declare the following to be a full and exact description thereof,reference being had to the accompanying drawing and letters of reference thereon.

The object of my improvement is to enable the engine-driver to work the steam-valves of large engines by hand, with much greater ease than otherwise could be done; and the manner of effecting that object is by combining an auxiliary steam-cylinder and piston with a reciprocating rock-shaft in such manner that the power of the steam in the auxiliary cylinder may be controlled by the hand of the engine-driver, to work the rock-shaft of the main engine at pleasure.

lThe principal value of this improvement is in enabling single puppet-valves to be used, which, when properly applied, will produce a saving of steam, as compared wit-h any balanced puppet-valves I have ever seen, of not less than ten per cent.; but with large balanced valves the same combination may be used with advantage to enable the valves to be opened much wider than can be done by hand with the starting-bar, and so Work the engine much more powerfully to back in cases of emergency.

In the accompanying drawing, three views are shown of the combination, and the same letters denote the same parts.

B is the side pipe of an ordinary engine.

R is the rock-shaft. A is the arm of the rock-shaft.

P is the ordinary pin for the eccentric hook X.

P2 is an additional pin to be used for the hook H, which is connected with the piston of a cylinder, C, so placed as to lead to the pin. This cylinder has a slide-valve ofthe ordinary construction, but may have any other sort of valve desired.

L is a lever, to one end of which the valvestem is attached, and the other end of which and by its motion to vibrate the rockshaft R, and of course open the valves ot' the main engine. In moving, however, the auxiliary piston, by means of the standard R, which travels With it, willcause the upper end of the lever L to move at the same rate, and if the starting-bar is held still, the effect will be that the valve of the auxiliary engine will again close by the motion of the auxiliary piston, and if it could move further it would open thel steam-valve at the opposite end of the auxiliary cylinder, and so arrest any further motion of the auxiliary piston. Thus the. auxiliary piston will follow the hand of the enginedriver, as he moves the startingbar-moving when it moves and stopping when it stops-j ust as if the rock-shaft itself were moved by the starting-bar directly in the usual manner; and of course the main engine rock-shaft can be moved to any degree and with any rate of speed required.

U is the unhooking-lever, which is so connected with the two hooks X and-H that as it is moved it will force oft' the hook H before the hook Xdrops on, so that no damage may be done.

Wis a weight arranged to force the hook A onto the pin P.

The method of controlling the small piston here shown is the best one I know; but other methods may be used, as a friction-brake attached to the small piston to preventtoo rapid action; driving a piston through a watercylinder, which piston should be connected with the small piston, and by the friction of the water retard it; lifting a pendulumweight, Which is connected with the small piston, and by raising which the small piston is retarded; and other Ways of applying the power of the auxiliary engine to the main valves may be used, as by a separate trip shaft, &c., and of course the arrangement here shown maybe modified an innnite numpiston of the auxiliary engine Will7 at the ber of Ways to suit different forms of engines pleasure ofthe engine-driver7 vibrate the roekhaving reciprocating rock-shafts which may shaft of the large engine, and thus open and be used, all of which, however, will comprise close the main valves which it Works, substanthis combination. tially as described.

What I claim as my invention and desire i J7 v to secure by Letters Patent', is-7 ED D' N' DLGERSON' The combination of an auxiliary steam-eyl- Witnesses: inder and piston with the vibrating rock-shaft L. PITKIN, of a large steam-engine, so arranged that the SAML. H. UORNWELL. 

